The present invention relates to a video edit system and a video browsing method which are capable of locating the head of each video or movie shot, included in a video having a plurality of video or movie shots, wherein each video or movie shot includes a series of uninterrupted video images photographed by one camera. More particularly, the present invention relates to a method and apparatus for detecting a point of change between video shots from a video stored on a video tape or video disk, wherein the video includes a plurality of succeeding frames.
With computer operation speed growing faster and the capacity of memory increasing in recent years, attention is now being focused on database systems and presentation tools which can handle movie and video information. Such information can not be sufficiently handled with conventional systems. Searching for only a desired part of a vast amount of video information and editing it is a time-consuming work.
Among the methods to alleviate editing work by using a computer a method disclosed in "Automatic Video Indexing and Full-Video Search for Object Appearances," Joho Shori Gakkai Ronbunshi (Collection of Papers, published by Information Processing Society), Vol. 33, No. 4, and Japan Patent Laid-Open No. 111181/1992 entitled "Change Point Detection Method in a Video" has been proposed. The above disclosed method involves automatically dividing a video for individual shots, preparing a list of images each representing a shot, and using them like indices of a book to aid in searching and editing of the video. The above disclosed method allows one to grasp the contents of a video at a glance using the list and to locate a desired scene. It is also possible to handle the video in units of a shot, which is an appropriate length for handling, and thereby make rough editing easy.
To divide the video into shots requires detecting a point of change between video shots in a video, i.e., a change in appearance of a first video shot relative to a second video shot. A conventional method of detecting a point of change between video shots in a video, as described in the above-mentioned Japan Patent Laid-Open No. 111181/1992, is based on a technique that decides that there is a point of change between video shots, i.e., a change in appearance between two succeeding frames of a video (frames are still images making up the motion picture wherein in television 30 images are displayed in each second) when there is an image difference between the two frames.
The above disclosed method, however, has a drawback in that it picks up as a point of change video shots having instantaneous disturbances of an image caused by strobe flashes produced when photographs are taken. These disturbances are such as those frequently encountered in press conferences, and by equipment trouble. Such image disturbances tend to occur successively during one shot, resulting in unwanted division of one shot. In a period of a video in which generally dark images of a night scene continue, the image difference between succeeding frames tends to be smaller than that of bright scenes. Hence, if the same reference is used for both dark scenes and bright scenes in determining a point of change, bright scenes may induce an overly sensitive reaction resulting in an erroneous detection of the point of change, while in dark scenes the point of change may fail to be detected.